<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title>边框</title>
		<style>
			*{
				margin: 0;
			}
			#d1,#t{
				border: 5px solid red;
				border-color: red  greenyellow black;
			}
			input#uname{
				border: none;
				outline-style: none;/*去轮廓*/
				border-bottom: 1px solid black;
			}
			#d3{
				border: 1px solid red;
				width: 400px;
				margin: 40px auto;/*水平居中*/
			}
		</style>
	</head>
	<body>
		<div id="d1">
			nihao 
		</div>
		
		<div>
			<a href="#" id="t">淘宝</a>
		</div>
		<div id="d3">
			<form>
				<p>
					<label for="uname">用户名</label>
					<input type="text" name="uname" id="uname"/>
				</p>
			</form>
		</div>
	</body>
</html>